UPD754144 데이터 시트보기 (PDF) - NEC => Renesas Technology

부품명

상세내역

제조사

UPD754144

4-BIT SINGLE-CHIP MICROCONTROLLERS

NEC => Renesas Technology 

µPD754144, 754244

4.2 Setting Method of Stack Bank Select Register (SBS)

Switching between the Mk I mode and Mk II mode can be done by the SBS. Figure 4-1 shows the format.

The SBS is set by a 4-bit memory manipulation instruction.

When using the Mk I mode, the SBS must be initialized to 1000B at the beginning of a program. When using

the Mk II mode, it must be initialized to 0000B.

Figure 4-1. Stack Bank Select Register Format

Address

F84H

3

2

1

0 Symbol

SBS3 SBS2 SBS1 SBS0 SBS

Stack area specification

0 0 Memory bank 0

Other than above setting prohibited

0 0 must be set in the bit 2 position

Mode switching specification

0 Mk II mode

1 Mk I mode

Caution Because SBS. 3 is set to “1” after a RESET signal is generated, the CPU operates in the

Mk I mode. When executing an instruction in the Mk II mode, set SBS. 3 to “0” to select

the Mk II mode.

14

Share Link: